Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -403,44 +403,37 @@ EXPORT_SYMBOL(acpi_bus_can_wakeup);
  * @dev: Device whose preferred target power state to return.
  * @adev: ACPI device node corresponding to @dev.
  * @target_state: System state to match the resultant device state.
- * @d_max_in: Deepest low-power state to take into consideration.
- * @d_min_p: Location to store the upper limit of the allowed states range.
- * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * @d_min_p: Location to store the highest power state available to the device.
+ * @d_max_p: Location to store the lowest power state available to the device.
  *
- * Find the lowest power (highest number) ACPI device power state that the
- * device can be in while the system is in the state represented by
- * @target_state.  If @d_min_p is set, the highest power (lowest number) device
- * power state that @dev can be in for the given system sleep state is stored
- * at the location pointed to by it.
+ * Find the lowest power (highest number) and highest power (lowest number) ACPI
+ * device power states that the device can be in while the system is in the
+ * state represented by @target_state.  Store the integer numbers representing
+ * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
+ * respectively.
  *
  * Callers must ensure that @dev and @adev are valid pointers and that @adev
  * actually corresponds to @dev before using this function.
+ *
+ * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
+ * returns a value that doesn't make sense.  The memory locations pointed to by
+ * @d_max_p and @d_min_p are only modified on success.
  */
 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
-				 u32 target_state, int d_max_in, int *d_min_p)
+				 u32 target_state, int *d_min_p, int *d_max_p)
 {
-	char acpi_method[] = "_SxD";
-	unsigned long long d_min, d_max;
+	char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
+	acpi_handle handle = adev->handle;
+	unsigned long long ret;
+	int d_min, d_max;
 	bool wakeup = false;
+	acpi_status status;
 
-	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
-		return -EINVAL;
-
-	if (d_max_in > ACPI_STATE_D3_HOT) {
-		enum pm_qos_flags_status stat;
-
-		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
-		if (stat == PM_QOS_FLAGS_ALL)
-			d_max_in = ACPI_STATE_D3_HOT;
-	}
-
-	acpi_method[2] = '0' + target_state;
 	/*
-	 * If the sleep state is S0, the lowest limit from ACPI is D3,
-	 * but if the device has _S0W, we will use the value from _S0W
-	 * as the lowest limit from ACPI.  Finally, we will constrain
-	 * the lowest limit with the specified one.
+	 * If the system state is S0, the lowest power state the device can be
+	 * in is D3cold, unless the device has _S0W and is supposed to signal
+	 * wakeup, in which case the return value of _S0W has to be used as the
+	 * lowest power state available to the device.
 	 */
 	d_min = ACPI_STATE_D0;
 	d_max = ACPI_STATE_D3_COLD;
@@ -449,12 +442,30 @@ static int acpi_dev_pm_get_state(struct
 	 * If present, _SxD methods return the minimum D-state (highest power
 	 * state) we can use for the corresponding S-states.  Otherwise, the
 	 * minimum D-state is D0 (ACPI 3.x).
-	 *
-	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
-	 * provided -- that's our fault recovery, we ignore retval.
 	 */
 	if (target_state > ACPI_STATE_S0) {
-		acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
+		/*
+		 * We rely on acpi_evaluate_integer() not clobbering the integer
+		 * provided if AE_NOT_FOUND is returned.
+		 */
+		ret = d_min;
+		status = acpi_evaluate_integer(handle, method, NULL, &ret);
+		if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
+		    || ret > ACPI_STATE_D3_COLD)
+			return -ENODATA;
+
+		/*
+		 * We need to handle legacy systems where D3hot and D3cold are
+		 * the same and 3 is returned in both cases, so fall back to
+		 * D3cold if D3hot is not a valid state.
+		 */
+		if (!adev->power.states[ret].flags.valid) {
+			if (ret == ACPI_STATE_D3_HOT)
+				ret = ACPI_STATE_D3_COLD;
+			else
+				return -ENODATA;
+		}
+		d_min = ret;
 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
 			&& adev->wakeup.sleep_state >= target_state;
 	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
@@ -470,36 +481,29 @@ static int acpi_dev_pm_get_state(struct
 	 * can wake the system.  _S0W may be valid, too.
 	 */
 	if (wakeup) {
-		acpi_status status;
-
-		acpi_method[3] = 'W';
-		status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
-						&d_max);
-		if (ACPI_FAILURE(status)) {
-			if (target_state != ACPI_STATE_S0 ||
-			    status != AE_NOT_FOUND)
+		method[3] = 'W';
+		status = acpi_evaluate_integer(handle, method, NULL, &ret);
+		if (status == AE_NOT_FOUND) {
+			if (target_state > ACPI_STATE_S0)
 				d_max = d_min;
-		} else if (d_max < d_min) {
-			/* Warn the user of the broken DSDT */
-			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
-				acpi_method);
-			/* Sanitize it */
-			d_min = d_max;
+		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
+			/* Fall back to D3cold if ret is not a valid state. */
+			if (!adev->power.states[ret].flags.valid)
+				ret = ACPI_STATE_D3_COLD;
+
+			d_max = ret > d_min ? ret : d_min;
+		} else {
+			return -ENODATA;
 		}
 	}
 
-	if (d_max_in < d_min)
-		return -EINVAL;
 	if (d_min_p)
 		*d_min_p = d_min;
-	/* constrain d_max with specified lowest limit (max number) */
-	if (d_max > d_max_in) {
-		for (d_max = d_max_in; d_max > d_min; d_max--) {
-			if (adev->power.states[d_max].flags.valid)
-				break;
-		}
-	}
-	return d_max;
+
+	if (d_max_p)
+		*d_max_p = d_max;
+
+	return 0;
 }
 
 /**
@@ -508,7 +512,8 @@ static int acpi_dev_pm_get_state(struct
  * @d_min_p: Location to store the upper limit of the allowed states range.
  * @d_max_in: Deepest low-power state to take into consideration.
  * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
+ * incorrect, or -ENODATA on ACPI method failure.
  *
  * The caller must ensure that @dev is valid before using this function.
  */
@@ -516,14 +521,39 @@ int acpi_pm_device_sleep_state(struct de
 {
 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 	struct acpi_device *adev;
+	int ret, d_max;
+
+	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
+		return -EINVAL;
+
+	if (d_max_in > ACPI_STATE_D3_HOT) {
+		enum pm_qos_flags_status stat;
+
+		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
+		if (stat == PM_QOS_FLAGS_ALL)
+			d_max_in = ACPI_STATE_D3_HOT;
+	}
 
 	if (!handle || acpi_bus_get_device(handle, &adev)) {
 		dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
 		return -ENODEV;
 	}
 
-	return acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
-				     d_max_in, d_min_p);
+	ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
+				    d_min_p, &d_max);
+	if (ret)
+		return ret;
+
+	if (d_max_in < *d_min_p)
+		return -EINVAL;
+
+	if (d_max > d_max_in) {
+		for (d_max = d_max_in; d_max > *d_min_p; d_max--) {
+			if (adev->power.states[d_max].flags.valid)
+				break;
+		}
+	}
+	return d_max;
 }
 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
@@ -674,17 +704,13 @@ struct acpi_device *acpi_dev_pm_get_node
 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
 				 u32 system_state)
 {
-	int power_state;
+	int ret, state;
 
 	if (!acpi_device_power_manageable(adev))
 		return 0;
 
-	power_state = acpi_dev_pm_get_state(dev, adev, system_state,
-					    ACPI_STATE_D3_COLD, NULL);
-	if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3_COLD)
-		return -EIO;
-
-	return acpi_device_set_power(adev, power_state);
+	ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
+	return ret ? ret : acpi_device_set_power(adev, state);
 }
 
 /**
